We've talked about groceries that are actually cheaper to make at home in the past, and this qualifies as one of them. According to Boing Boing's Xeni Jardin, the result of this recipe is a product that "costs five to 10 times less than the store-bought stuff." All that you need is a small cup of regular yogurt to use as a starter culture, milk, and a bit of space in your oven to let the yogurt set.

Note that while you only need to put in 20 minutes of work, the yogurt actually requires four to five hours to set. Use that time to make some granola, and together with some fresh fruit you'll have a healthy summer treat. Thanks, Seth!